This invention relates to hoists and cranes mounted to vehicles and particularly to hoists that use a trailer hitch as a structural attachment.
Pickup trucks are versatile vehicles used for hauling cargo. Many pickup trucks are used by businesses for delivering merchandise and transporting goods. Often the cargo transported is not easily loaded and unloaded. When people make the effort to load and unload heavy goods from the raised bed of a pickup truck they risk personal injury, particularly to the lower back.
In order to help people load and unload cargo from small trucks, a variety of small hoists suitable for attachment to a conventional trailer hitch have been developed. For example, in U.S. Pat. No. 4,746,263, Cook describes a small retractable hoist. This hoist is mounted to the bumper of a pickup truck and, when it is not needed, is stored in the bumper. This hoist is compact and versatile however the truck directly supports the load that the hoist lifts. Clearly, if heavy loads are to be lifted then the structure of the truck proximate the bumper should be reinforced. Otherwise, the structural supports for the bumper are being used in a way that they were not intended and in the event that a very heavy load is lifted, the crashworthiness of the truck may be compromised.
In U.S. Pat. No. 4,419,038, Pendergraft also teaches a hoist design for a small truck. The hoist taught by Pendergraft also folds into a large rear vehicle bumper. This hoist optionally features structural supports that increase the effective width of the truck when the hoist is properly deployed. Although this hoist has the potential to be very sturdy, it also is likely to be very costly. Additionally, the hoist taught by Pendergraft is raised from one side of the truck. Clearly, this would be inconvenient if it were necessary to load the truck from the opposite side.
In U.S. Pat. No. 4,226,331, Dumond teaches the design of a hoist for use with a three-point hitch of a tractor. This design uses hydraulic actuators for movement. The hoist is notable in that it features supports that contact the ground proximate the load bearing member of the hoist. This structure complicates the mounting of a trailer to the tractor when the hoist is deployed.
In U.S. Pat. No. 6,042,328, McVaugh demonstrates a lifting device for a small truck that is shown attaching directly to a trailer hitch attachment. The lifting device is shown spanning a considerable length of the bed of the truck. Since this device does not include an external support, the weight of the lift and any load that it carries are supported exclusively by the trailer hitch. A lifting device of this type produces substantial torque at the trailer hitch attachment. Unless the trailer hitch is designed to bear this type of load it is most probable that the trailer hitch is damaged when the lift is used.
It would be beneficial to have a small, cost effective hoist for pickup trucks that is easily transportable, supports heavy loads and does not involve a costly structural modification to the pickup trucks. Additionally, it would be beneficial that such a hoist be collapsible for ease of storage.
The invention describes a hoist kit adapted for engagement with and structural support by a receiver hitch attachment, comprising: A hoist mount having a first end (insert), a second end (tongue) and a hinged joint disposed therebetween which provides rotational approximately lateral movement of the second end relative to the hinged joint when the first end is fixed, the first end which mechanically engages the receiver hitch;
a jib post which extends approximately vertically, said jib post which is mechanically coupled to the second end of the hoist mount;
a rotational boom support coupled to the jib post;
a boom which extends from the boom support, said boom which bears a weight of an external load; and,
a first leg which is mechanically coupled proximate the second end of the hoist mount allowing pivotal motion relative thereto between a first position which contacts a region of ground proximate a vehicle supporting said receiver hitch attachment which structurally supports the hoist mount and a second refracted position.
Further the invention discloses a hoist kit adapted for engagement with and structural support by a receiver hitch attachment, comprising:
a hoist mount having a first end (insert) which mechanically engages a receiver hitch attachment, a second end (tongue) and a hinged joint disposed therebetween which provides approximately lateral movement of the second end relative to the hinged joint when the first end is fixed;
a jib post extending approximately vertically, said jib post mechanically coupled to the second end of the hoist mount;
a rotational boom support coupled to the jib post,
a boom extending from the boom support, said boom which bears a weight of an external load; and,
a first leg mechanically coupled proximate the second end of the hoist mount which allows pivotal motion relative thereto between a first position which contacts a region of ground proximate a vehicle supporting said receiver hitch attachment and which structurally supports the hoist mount and a second retracted position.
Additionally, the invention details a hoist kit adapted for engagement with and structural support by a receiver hitch attachment, comprising:
a hoist mount having a first end (insert) a second end (tongue) and a hinged joint disposed therebetween for providing rotational approximately lateral movement of the second end relative to the hinged joint when the first end is fixed, the first end which mechanically engages the receiver hitch;
a jib post which extends approximately vertically, said jib post mechanically coupled to the second end of the hoist mount;
a rotational boom support coupled to the jib post;
a boom extending from the boom support, said boom which bears a weight of an external load; and,
a first leg coupled to one of said boom and said jib post which engages the ground and which supports the boom and a load supported thereby.